Microsoft is all set to end official support for Windows XP on April 8, 2014. And the operating system that took over the world after launching nearly 12 years ago will finally stop receiving security updates beyond this date.

And rightly so, Redmond has been sending off warning signals, cautioning the (still rather large) Windows XP user base about the security risks that the old operating system could pose for their PCs.

But while Windows XP patches will not be released for end consumers, this does not mean that Redmond will stop developing for the platform all together. As Computerworld notes, Microsoft does indeed offer something called Custom Service.

This premium development service, aimed primarily at large businesses and organizations, allows certain Windows XP machines to keep getting updates.

A data sheet for Custom Service quoted in the article says:

“Legacy products or out-of-support service packs covered under Custom Support will continue to receive security hotfixes for vulnerabilities labeled as ‘Critical’ by the MSRC [Microsoft Security Response Center]. Customers with Custom Support that need security patches defined as ‘Important’ by MSRC can purchase these for an additional fee.”

The report further adds that Microsoft does not publish their Custom Service fees publicly, as they are negotiated on a company by company basis. But it is speculated that the cost to patch a PC under such a plan hovers around $200 for the first year, just to get the Critical security fixes.

In other words, it makes all sorts of sense for most Windows XP users to pay for an upgrade to either Windows 7 or Windows — save for the very few that cannot or do not want to, because of software incompatibility or other such issues.